2002 Bluenose-East Caribou Contaminant Study

Summary

This report summarises the data from the analysis of liver and kidney tissues from caribou collected south and west of Deline, NT in March, 2002. The samples were analysed by ICP/MS for a full suite of twenty-two metals by Taiga Laboratory in Yellowknife. The same tissues were analysed for naturally occurring radionuclides and cesium-137 by Whiteshell Laboratories in Pinawa, MB.Most metals were detected in the two tissues in all the caribou harvested, however beryllium, lithium and uranium were not detected in any sample. Other metals, like aluminum, thallium, and silver were only detectable in a few samples of either liver or kidney. Metals of concern, like cadmium and mercury, are relatively low in these animals and are not expected to be a danger to the animals or people who hunt them.Several natural radionuclides were measured in the tissues, but all levels remain within the normal range found in caribou in the North. Potassium-40, a natural nuclide found in all living tissues, remained at slightly less than 100 Bq/kg, consistent with all other caribou. Uranium-235, radium-226 and thorium-232 are all natural nuclides that form from the decay of uranium-238, but are found at very low concentrations in these animals. Lead-210 and polonium-210, two natural nuclides, are present at levels within the ranges normally found for caribou in the NWT. Although meat wasn’t tested in this study, it is expected from other studies that these isotopes would be <10 Bq/kg in meat. These data indicate that there is no evidence of contamination of metals or radionuclides, and that the caribou meat remains a healthy, nutritious food source.